Sachin Sant wrote:

Tejun Heo wrote:

quoted

Can you please apply the attached patch and see whether anything
interesting shows up in the kernel log?
  

Thanks Tejun for the debug patch. Attached here are the relevant logs.
The only messages related to percpu in the logs are

<6>PERCPU: Embedded 2 pages/cpu @c000000001200000 s100232 r0 d30840 u524288
<7>pcpu-alloc: s100232 r0 d30840 u524288 alloc=1*1048576
<7>pcpu-alloc: [0] 0 1
The captured logs are with latest git.

Hmm... that means it wasn't caused by rogue percpu pointer access.
Pleast wait a bit.  I'll try to reproduce it.

Thanks.

-- 
tejun